Information processing by the skin senses (tactile systems) may be utilized when the effectiveness of a conventional channel is limited, as in high noise environments, or when existing channels are overtaxed, as in jet and space control systems. A humane and also practical aspect of the research is its applicability in compensating for sensory losses of the blind and deaf. Before these needs may be satisfied, sizeable gaps must be filled in our knowledge of the basic functioning of the cutaneous sensory systems. The aim of the proposed experiments is to extend our knowledge of the psychophysical responses to vibrotactile stimulation in humans. The experiments fall into four problem areas: 1) the effects of stimulus duration on vibrotactile responses; 2) vibrotactile poststimulatory effects; 3) intrasensory interactions between mechanoreceptor systems; and 4) intersensory interactions among vibrotaction, audition and vision. BIBLIOGRAPHIC REFERENCES: Verrillo, R. T. and Smith, R. L. Effect of stimulus duration on vibrotactile sensation magnitude. Bulletin of the Psychonomic Society, 1976, 8, 112-114. Barlow, R. B. and Verrillo, R. T. Brightness sensation in a ganzfeld. Vision Research, 1976, 16, 1291-1297.